SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f8cc6c993d7bce5b1f1c757ea9b43133dda42a231910e1cc80c7390a312724f' 
  AND token = 'Z23NmvUE1XSvuQt88k6A9zYmZJ7RVhz1XJKyP1iDIWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}